osx man page for fade_interpolate

fade_interpolate(3alleg4)					  Allegro manual					 fade_interpolate(3alleg4)

NAME

       fade_interpolate - Calculates a new palette interpolated between two others. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

       void fade_interpolate(const PALETTE source, const PALETTE dest, PALETTE output, int pos, int from, int to);

DESCRIPTION

       Calculates  a  temporary  palette  part	way  between  source  and dest, returning it in the output parameter. The position between the two
       extremes is specified by the pos value: 0 returns an exact copy of source, 64 returns dest, 32 returns a palette half way between the  two,
       etc. This routine only affects colors between from and to (inclusive: pass 0 and 255 to interpolate the entire palette).

SEE ALSO

       fade_in(3alleg4), fade_out(3alleg4), fade_from(3alleg4)

Allegro 							   version 4.4.2					 fade_interpolate(3alleg4)